1. Export FBX from blender with binary(off Armature->AddLeafBones).
2. Drag and drop the FBX file to the Unity.
3. Set the Root to the rootnode.
1. Set the frame rate 30fps.
Export FBX from blender with binary(off Armature->AddLeafBones).
2. Import the fbx file to 3dsMax with unit as meter and chose animationtake(usually *ArmatureAction).
3.Delete the armature.
4.Export the FBX with unit as automatic.
5.Drag and drop the FBX to UE4.
To import the animation check "Use default settings".
However, in the unit system of UE 4, the size of the mesh is about one hundredth.
The procedure to change the scale of the model is posted in the following article.